A rara avis amongst birettas

The Clever Boy being the sort of person who notices these things he felt rather like a bird-watcher
 ( aka a Twitcher) who had spotted a lesser-spotted blue hook-beaked dotteril or what have you when he noted the biretta worn by Bishop Robert Byrne at Vespers at the Oxford Oratory this evening. This was an episcopal biretta in Roman Purple, but fashioned according to the Oratorian model. That, if readers are not familiar with it, is with slightly shallower sides that other designs and having a cord stalk rather than a pom-pom at the summit.

Now given the rarity of Oratorian bishops, and there has not been one in England since 1917, this was a rare sighting indeed and one to put on record. I commented upon it to Bishop Robert, and I thought its existence should be bruited abroad.